1. Field of the Invention
The invention relates to an aluminum nitride material and a member for use in the production of semiconductors.
2. Related Art Statement
An electrostatic chuck system utilizing Johnson-Rahbek effect is useful for the adsorption and retention of semiconductor wafers. In such system, the volume resistivity of the substrate of the chuck may preferably be 108 to 1013 Ω·cm for improving adsorption force and speed of response. It is therefore desirable to control the volume resistivity of the substrate within 108 to 1013 Ω·cm in a temperature range intended for use, in the development of an electrostatic chuck.
For example, the assignee filed Japanese patent publication 9-315, 867A and disclosed a method of adding a trace amount of yttrium oxide into aluminum nitride having a high purity to control the volume resistivity at room temperature at a value between 108 to 1013 Ω·cm.
The assignee has further filed U.S. Patent publication 2002-0110709A1 and disclosed an aluminum nitride sintered body containing samarium in a content of 0.04 mole percent or more to generate continuous samarium-aluminum oxide phase. The thus obtained sintered body has a volume resistivity of 1012 Ω·cm or lower at room temperature.